Antifriction device

ABSTRACT

An antifriction device is provided for reducing friction forces which impede relative movement between a ski boot and a ski in all directions in a plane parallel with the toe portion of the ski boot under fall conditions. In its simplest form, the device comprises a plate on which is fixedly mounted and retained one or more arcuate members. A portion of the arcuate surface of the members is adapted to make contact with the toe portion of the ski boot or a plane rigid plate mounted to the toe portion of the ski boot. In a further embodiment of the device, a hollow housing is provided and adapted to retain a member having an arcuate surface such as a ball bearing which is free to rotate within the housing and which projects through an aperture in the housing to make contact with the toe of the ski boot or the plate. The housing is further provided with a cavity to receive lubricant for lubricating the retained member.

United States Patent [191 Spademan ANTIFRICTION DEVICE [76] Inventor: Richard G. Spademan, 933 Addison Ave., Palo Alto, Calif. 94301 [22] Filed: Feb. 17, 1972 211 Appl. No.: 227,119

[52] 11.8. C1 280/11.35 C [51] Int. Cl. A63c 9/08 [58] Field of Search280/1 1.35 C, 11.35 D, 11.35 R,

280/ll.35 B, 11.12; 308/203 FOREIGN PATENTS OR APPLICATIONS 65,092

Primary Examiner-Richard J. Johnson Assistant Examiner-Reinhard J. Eisenzopf 7 TNT 7/1942 Norway 280/1 1.35 B

[451 Aug. 13, 1974 [57] ABSTRACT An antifriction device is provided for reducing friction forces which impede relative movement between a ski boot and a ski in all directions in a plane parallel with the toe portion of the ski boot under fall conditions. In its simplest form, the device comprises a plate on which is fixedly mounted and retained one or more arcuate members. A portion of the arcuate surface of the members is adapted to make contact with the toe portion of the ski boot or a plane rigid plate mounted to the toe portion of the ski boot. In a further embodiment of the device, a hollow housing is provided and adapted to retain a member having an arcuate surface such as a ball bearing which is free to rotate within the housing and which projects through an aperture in the housing to make contact with the toe of the ski boot or the plate. The housing is further provided with a cavity to receive lubricant for lubricating the retained member.

8 Claims, 7 Dr aw ing Figures ANTIFRICTION DEVICE BACKGROUND OF THE INVENTION It is well known that in a slow forward and twisting fall, the pressure and friction between the surface of a ski and the bottom of a ski boot under the ball of the foot increases substantially. In some cases this increased friction can be of sufficient magnitude to reduce the safety release factor of a release binding. Several antifriction devices have been proposed, but all have in common the deficiency of being subject to the effect of the composition and geometry of the bottom of the boot sole. In addition, several of these devices are grossly subject to the effects of dirt and debris. Others do not provide sufficient travel to'allow the boot to release the binding without considerable increase in friction when the maximum travel of the device is reached. Further, the known devices function generally only in a lateral direction.

SUMMARY OF THE INVENTION An object of the present invention is'an antifriction device which overcomes the disadvantages of the prior known devices and substantially decreases friction forces between the boot bottom at the ball of the foot and the ski in all directions parallel to the bottom of the boot in a forward and twisting fall.

A feature of the present invention is a plate on which is mounted and retained one or more members having an arcuate surface. A portion of the arcuate surface of said members makes contact with the boot bottom at the ball of the foot. The minimum amount of surface contact between and the relative hardness of the arcuate surface and the bottom of the average boot results in the reduction of friction forces during relative movement between the boot bottom and the ski.

In a further embodiment of the invention, there is provided a hollow housing in which is retained one or more arcuate members. In this embodiment the arcuate members preferably comprise a spherical ball, such as a ball hearing. A portion of the arcuate sufrace of the ball projects through an aperture in the housing to make contact with the bottom of the boot. A cavity is further provided in the hollow housing to receive a lubricant for lubricating the balls which are free to rotate about an axis transverse to the direction of movement between the ski boot and the ski.

For use with either embodiment there is further provided a relatively rigid plane plate which is adapted for mounting to the boot bottom and serves as a bearing surface for the arcuate members. The plate is used when the boot bottom surface is not smooth or is relatively soft.

These and other objects, features and advantages of the present invention will be apparent from the following detailed description and accompanying drawings of the present invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of one embodiment of the present invention wherein arcuate members are fixedly mounted to a rigid plate;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

. FIG. 3 is a plan view of another embodiment of the present invention wherein arcuate members are free to rotate within a hollow housing;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a bottom view of the housing of FIGS. 35 only;

FIG. 7 is an exploded view of FIGS. 3-6.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, there is provided, in accordance with the present invention, a plate 1. Plate I is in the form of a rigid plate which serves as a retention means on which is mounted and retained in any suitable manner one or more arcuate members 2. Arcuate members 2 are preferably in the form or shape of a hemisphere and preferably constructed of a hard noncorrosive material, such as stainless steel. Plate 1 is further provided with one or more means, such as recessed screw holes 3, for mounting plate 1 to the upper surface of a ski. Alternatively, plate I may be cemented or riveted to a ski in any conventional manner.

Members 2 are fixedly mounted and retained in any well known manner on the upper surface of plate 1 and adapted in use to make contact with a forward portion of the sole of a ski boot in the vicinity of the toe portion of the ski boot at the ball of the foot.

The limited area of contact between the boot bottom and the arcuate surfaces of members 2 aids in reducing the friction forces which are otherwise created between a boot toe and a ski under forward fall conditions.

For use with ski boots having an uneven or rough sole, or in cases where the sole portion making contact with members 2 is relatively soft, there is further provided a plane plate 4. Plate 4 is preferably made of a hard smooth rigid material and is further provided with one or more means, such as, recessed screw holes 6, for mounting plate 4to a forward portion of a ski boot bottom such as at the ball of the foot for making contact with and serving as a bearing surface for members 2 mounted on plate 1. It is understood that alternative means maybe used for mounting plate 4 to a ski boot bottom if desired. Another embodiment of the present invention is shown in FIGS. 3-7. Referring to FIGS. 3-7, there is provided a hollow housing 10 having an upper surface 11 and a lower surface 12 enclosing a cavity 13. Housing 10 serves as a retention means and captured within housing 10 are one or more arcuate members 15.

The upper surface 11 of housing 10 is further provided with one or more conically shaped apertures 16 through which a limited portion 17 of each of members 15 is projected. The size and shape of apertures 16 conforms with the general shape of and mates with members 15 and serves to retain members 15 within housing 10. The lower portion of members 15 rests on the upper surface of lower surface 12 of housing 10. Alternatively, a mating recess (not shown) may be provided in surface 12 for receiving members 15. Such a recess would serve to reduce wearing of the surfaces of apertures 16 by aiding the retention function of apertures 16.

Housing 10 is further provided with one or more means such as screw holes 19, for mounting housing 10 to the upper surface of a ski under the toeportion of 3 a ski boot in the manner described with respect to plate 1 of FIGS. 1 and 2.

As described with respect to members 2 of FIGS. 1 and 2, arcuate members 15 are preferably made of a hard noncorrosive material such as stainless steel. For even greater reduction in friction forces which are created during forward and twisting fall conditions, sufficient clearance is provided between apertures 16 and members 15 to permit members 15 to rotate about an axis transverse the direction of motion between the ski boot and ski under fall conditions. Accordingly, members 15 are preferably spherically shaped and will take the form of an ordinary ball bearing.

As described with respect to the device of FIGS. 1 and 2, plate 4 is also adapted to cooperate in working relationship with members 15 to providea smooth rigid bearing surface for members 15 when the device of the present invention is used with ski boots having a soft sole or an irregular sole bottom.

It is apparent that roller, taper, or a combination of such bearings can be used in lieu of ball bearings and that a smooth relatively rigid surface boot sole will not require plate 4. I

In practice the bottom surface 12 of housing which supports members 15 may be recessed in housing 10 or may abut against the vertical walls of housing 10 and held in place by screws passing through screw holes 19 as shown in FIGS. 4 and 5.

When assembled, cavity 13 of housing 10 may be filled with an appropriate lubricant for lubricating the surfaces of members 15.

Referring to FIG. 6, there is further provided in the interior of housing 10, supporting members 20 and 21 which serve to strengthen the upper surface 11 and mounting screw holes 19, respectively.

FIG. 7 is an exploded view of FIGS. 3-6 and further illustrates the cooperative relationship between plate 4 and arcuate members 15.

It is understood that the above-mentioned and other modifications of the present invention will be apparent to those skilled in the art without departing from the scope of the invention as hereinafter claimed.

What is claimed is 1. An antifriction device for use between a ski and a ski boot comprising: a retention means; means retained by said retention means for contacting a forward portion of said ski boot for reducing friction forces impeding relative movement between said forward portion of said ski boot and said ski in all directions in a plane parallel with said forward portion of said ski boot under fall conditions; and means for mounting said retention means to the upper surface of said ski, and wherein said means retained by said retention means comprises a spherical surface and wherein said spherical surface makes direct contact with said forward portion of said ski boot.

2. An antifriction device according to claim 1 wherein said retention means is a hollow housing and further comprising: an aperture in a surface of said housing; means for mounting said retained means within said aperture and wherein at least a portion of said spherical surface of said retained means projects through said aperture for making said contact with said forward portion of said ski boot.

3. An antifriction device according to claim 2 wherein said retained means is free to move when there is relative motion between said ski and said forward portion of said ski boot.

4. An antifriction device according to claim 3 wherein said movement of said retained means is rotational about an axis transverse the direction of relative movement between said ski and said forward portion of said ski boot.

5. An antifriction device according to claim 3 further comprising: a plate having a plane surface; means for mounting said plate to said ski boot whereby said plate becomes said forward portion of said ski boot which makes contact with said spherical surface of said retained means.

6. An antifriction device according to claim 3 wherein said housing further comprises a cavity for receiving a lubricant for lubricating said retained means.

7. An antifriction device according to claim 1 further comprising: a plate having a plane surface; means for mounting said plate to said ski boot whereby said plate becomes said forward portion of said ski boot which makes contact with said spherical surface of said retained means.

8. An antifriction device according to claim 1 wherein said spherical surface which makes contact with said forward portion of said ski boot moves when there is relative motion between said ski and said forward portion of said ski boot. I 

1. An antifriction device for use between a ski and a ski boot comprising: a retention means; means retained by said retention means for contacting a forward portion of said ski boot for reducing friction forces impeding relative movement between said forward portion of said ski boot and said ski in all directions in a plane parallel with said forward portion of said ski boot under fall conditions; and means for mounting said retention means to the upper surface of said ski, and wherein said means retained by said retention means comprises a spherical surface and wherein said spherical surface makes direct contact with said forward portion of said ski boot.
 2. An antifriction device according to claim 1 wherein said retention means is a hollow housing and further comprising: an aperture in a surface of said housing; means for mounting said retained means within said aperture and wherein at least a portion of said spherical surface of said retained means projects through said aperture for making said contact with said forward portion of said ski boot.
 3. An antifriction device according to claim 2 wherein said retained means is free to move when there is relative motion between said ski and said forward portion of said ski boot.
 4. An antifriction device according to claim 3 wherein said movement of said retained means is rotational about an axis transverse the direction of relative movement between said ski and said forward portion of said ski boot.
 5. An antifriction device according to claim 3 further comprising: a plate having a plane surface; means for mounting said plate to said ski boot whereby said plate becomes said forward portion of said ski boot which makes contact with said spherical surface of said retained means.
 6. An antifriction device according to claim 3 wherein said housing further comprises a cavity for receiving a lubricant for lubricating said retained means.
 7. An antifriction device according to claim 1 further comprising: a plate having a plane surface; means for mounting said plate to said ski boot whereby said plate becomes said forward portion of said ski boot which makes contact with said spherical surface of said retained means.
 8. An antifriction device according to claim 1 wherein said spherical surface which makes contact with said forward portion of said ski boot moves when there is relative motion between said ski and said forward portion of said ski boot. 